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Related papers: Generalized unitarity for N=4 super-amplitudes

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We prove that 1-loop n-point NMHV superamplitudes in N=4 SYM theory are dual conformal covariant for all numbers n of external particles (after regularization and subtraction of IR divergences). This property was previously established for…

High Energy Physics - Theory · Physics 2015-05-13 Henriette Elvang , Daniel Z. Freedman , Michael Kiermaier

In this paper a supersymmetric version of a generalized unitarity cut method in application to MHV and NMHV for form factors of operators from the N=4 SYM stress-tensor current supermultiplet $T^{AB}$ at one loop is discussed. The explicit…

High Energy Physics - Theory · Physics 2015-06-04 L. V. Bork

Using four-dimensional unitarity and MHV-rules we calculate the one-loop MHV amplitudes with all external particles in the adjoint representation for N=2 supersymmetric QCD with N_f fundamental flavours. We start by considering such…

High Energy Physics - Theory · Physics 2014-11-18 E. W. Nigel Glover , Valentin V. Khoze , Ciaran Williams

We argue that the scattering amplitudes in the maximally supersymmetric N=4 super-Yang-Mills theory possess a new symmetry which extends the previously discovered dual conformal symmetry. To reveal this property we formulate the scattering…

High Energy Physics - Theory · Physics 2009-12-22 J. M. Drummond , J. Henn , G. P. Korchemsky , E. Sokatchev

Recent studies of scattering amplitudes in planar N=4 SYM theory revealed the existence of a hidden dual superconformal symmetry. Together with the conventional superconformal symmetry it gives rise to powerful restrictions on the planar…

High Energy Physics - Theory · Physics 2014-11-20 G. P. Korchemsky , E. Sokatchev

In addition to the superconformal symmetry of the underlying Lagrangian, the scattering amplitudes in planar N=4 super-Yang-Mills theory exhibit a new, dual superconformal symmetry. We address the question of how powerful these symmetries…

High Energy Physics - Theory · Physics 2010-03-17 G. P. Korchemsky , E. Sokatchev

A study of the colour-ordered one-loop amplitudes in N=4 SYM reveals a surprising property: numerically, the amplitudes have an Approximately Universal form A^{1-loop}_n ~ A^{tree}_n \times U_n, where U_n is helicity independent. This form…

High Energy Physics - Theory · Physics 2009-03-27 David C. Dunbar , James H. Ettle , Warren B. Perkins

In this letter, we exploit generalised unitarity in order to calculate the cut-constructible part of one-loop amplitudes in non-supersymmetric Yang-Mills theory. In particular, we rederive the n-gluon MHV amplitudes for both the adjacent…

High Energy Physics - Phenomenology · Physics 2010-02-03 Andreas Brandhuber , Massimiliano Vincon

In this paper we describe algebraic and diagrammatic methods, related to the MHV generating function method, for evaluating and exposing the structure of supersymmetric sums over the states crossing generalized unitarity cuts of multi-loop…

High Energy Physics - Theory · Physics 2013-05-29 Z. Bern , J. J. M. Carrasco , H. Ita , H. Johansson , R. Roiban

Over the past two years, the use of on-shell techniques has deepened our understanding of the S-matrix of gauge theories and led to the calculation of many new scattering amplitudes. In these notes we review a particular on-shell method…

High Energy Physics - Theory · Physics 2017-08-23 Andreas Brandhuber , Gabriele Travaglini

Recently, it has been shown that the holomorphic anomaly of unitarity cuts can be used as a tool in determining the one-loop amplitudes in N=4 super Yang-Mills theory. It is interesting to examine whether this method can be applied to more…

High Energy Physics - Theory · Physics 2010-11-15 Steven J. Bidder , N. E. J. Bjerrum-Bohr , Lance J. Dixon , David C. Dunbar

This thesis is focused on the development of new mathematical methods for computing multi-loop scattering amplitudes in gauge theories. In this work we combine, for the first time, the unitarity-based construction for integrands, and the…

High Energy Physics - Phenomenology · Physics 2014-10-21 Ulrich Schubert

One-loop amplitudes of gluons in N=4 gauge theory can be written as linear combinations of known scalar box integrals with coefficients that are rational functions. In this paper we show how to use generalized unitarity to basically read…

High Energy Physics - Theory · Physics 2009-11-10 Ruth Britto , Freddy Cachazo , Bo Feng

Here we construct N=4 SuperYang-Mills 6 point NMHV loop amplitude (amplitudes with three minus helicities) as a full superspace form, using the $SU(4)_{R}$ anti-commuting spinor variables. Amplitudes with different external particle and…

High Energy Physics - Theory · Physics 2009-11-11 Yu-tin Huang

We compute four-point scattering amplitudes in $\mathcal{N}=2$ SCQCD with general external matter configurations using $\mathcal{N}=1$ superspace Feynman diagrams, at one loop in the general case and up to two loops in the fundamental…

High Energy Physics - Theory · Physics 2015-01-22 Marta Leoni , Andrea Mauri , Alberto Santambrogio

For three dimensional N=6 superconformal field theories we compute one-loop scattering amplitudes for any number of external particles. We focus on a particular subsector of N=2 invariant superamplitudes for which the ordinary perturbative…

High Energy Physics - Theory · Physics 2012-07-11 Marco S. Bianchi , Matias Leoni , Andrea Mauri , Silvia Penati , Alberto Santambrogio

Recent progress in unitarity techniques for one-loop scattering amplitudes makes a numerical implementation of this method possible. We present a 4-dimensional unitarity method for calculating the cut-constructible part of amplitudes and…

High Energy Physics - Phenomenology · Physics 2009-09-17 R. K. Ellis , W. T. Giele , Z. Kunszt

We review generalized unitarity as a means for obtaining loop amplitudes from on-shell tree amplitudes. The method is generally applicable to both supersymmetric and non-supersymmetric amplitudes, including non-planar contributions. Here we…

High Energy Physics - Theory · Physics 2015-05-27 Zvi Bern , Yu-tin Huang

Recently, the spinor helicity formalism and on-shell superspace were developed for six-dimensional gauge theories with (1,1) supersymmetry. We combine these two techniques with (generalised) unitarity, which is a powerful technique to…

High Energy Physics - Theory · Physics 2011-03-02 Andreas Brandhuber , Dimitrios Korres , Daniel Koschade , Gabriele Travaglini

We review the structure of gauge theory scattering amplitudes at tree level and describe how a compact expression can be found which encodes all the tree-level amplitudes in the maximally supersymmetric N=4 theory. The expressions for the…

High Energy Physics - Theory · Physics 2015-05-28 J. M. Drummond
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